Hey there, I was wondering if someone could help me out, I'm kinda at a loss at where I am in the first game.

I'm about to get the Spandam/Aokiji bosses, I made the icicles fall (Island 3) but there is still one of those poison walls in the way which I haven't been able to do anything about since I first encountered them.

So how do I get past them, if I need to upgrade my hoover how do I do so? I tried googling and it said to unlock the 8th treasure, but I have no idea what the '8th treasure' is to be perfectly honest.

Thanks (: